.common-header{
  height: 50px;
  margin:0 auto;
  background: #fff;
  border-bottom:1px solid #f3f3f3;
  position: relative;
  .logo{
    height: 30px;
    position: absolute;
    top:10px;
    left:10px;
  }
  .nav{
    height: 50px;
    float: right;
    margin-right: 20px;
    li{
      float: left;
      height: 50px;
      line-height: 50px;
      padding:0 5px;
      a{
        color: #686868;
      }
    }
    .user{
      background: url(./image/user.png) no-repeat left center;
      background-size:auto 14px;
      padding-left:15px;
    }
  }
}